From: Wen Congyang <wency@cn.fujitsu.com>
To: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
Tang Chen <tangchen@cn.fujitsu.com>,
linux-mm@kvack.org, paulus@samba.org, hpa@zytor.com,
sparclinux@vger.kernel.org, cl@linux.com,
linux-s390@vger.kernel.org, x86@kernel.org,
linux-acpi@vger.kernel.org, isimatu.yasuaki@jp.fujitsu.com,
linfeng@cn.fujitsu.com, mgorman@suse.de,
kosaki.motohiro@jp.fujitsu.com, rientjes@google.com,
liuj97@gmail.com, len.brown@intel.com, cmetcalf@tilera.com,
wujianguo@huawei.com, yinghai@kernel.org, laijs@cn.fujitsu.com,
linux-kernel@vger.kernel.org, minchan.kim@gmail.com,
akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v5 14/14] memory-hotplug: free node_data when a node is offlined
Date: Sun, 30 Dec 2012 14:02:28 +0800 [thread overview]
Message-ID: <50DFD8F4.7040301@cn.fujitsu.com> (raw)
In-Reply-To: <50DCE7C0.8070407@jp.fujitsu.com>
At 12/28/2012 08:28 AM, Kamezawa Hiroyuki Wrote:
> (2012/12/27 21:16), Wen Congyang wrote:
>> At 12/26/2012 11:55 AM, Kamezawa Hiroyuki Wrote:
>>> (2012/12/24 21:09), Tang Chen wrote:
>>>> From: Wen Congyang <wency@cn.fujitsu.com>
>>>>
>>>> We call hotadd_new_pgdat() to allocate memory to store node_data. So we
>>>> should free it when removing a node.
>>>>
>>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>>>
>>> I'm sorry but is it safe to remove pgdat ? All zone cache and zonelists are
>>> properly cleared/rebuilded in synchronous way ? and No threads are visinting
>>> zone in vmscan.c ?
>>
>> We have rebuilt zonelists when a zone has no memory after offlining some pages.
>>
>
> How do you guarantee that the address of pgdat/zone is not on stack of any kernel
> threads or other kernel objects without reference counting or other syncing method ?
No way to guarentee this. But, the kernel should not use the address of pgdat/zone when
it is offlined.
Hmm, what about this: reuse the memory when the node is onlined again?
Thanks
Wen Congyang
>
>
> Thanks,
> -Kame
>
>
>
next prev parent reply other threads:[~2012-12-30 5:55 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-24 12:09 [PATCH v5 00/14] memory-hotplug: hot-remove physical memory Tang Chen
2012-12-24 12:09 ` [PATCH v5 01/14] memory-hotplug: try to offline the memory twice to avoid dependence Tang Chen
2012-12-25 8:35 ` Glauber Costa
2012-12-30 5:58 ` Wen Congyang
2013-01-09 15:09 ` Glauber Costa
2013-01-10 1:38 ` Tang Chen
2013-02-06 3:07 ` Tang Chen
2013-02-06 9:17 ` Tang Chen
2013-02-06 10:10 ` Tang Chen
2013-02-06 14:24 ` Glauber Costa
2013-02-07 7:56 ` Tang Chen
2012-12-26 3:02 ` Kamezawa Hiroyuki
2012-12-30 5:49 ` Wen Congyang
2012-12-24 12:09 ` [PATCH v5 02/14] memory-hotplug: check whether all memory blocks are offlined or not when removing memory Tang Chen
2012-12-26 3:10 ` Kamezawa Hiroyuki
2012-12-27 3:10 ` Tang Chen
2012-12-24 12:09 ` [PATCH v5 03/14] memory-hotplug: remove redundant codes Tang Chen
2012-12-26 3:20 ` Kamezawa Hiroyuki
2012-12-27 3:09 ` Tang Chen
2012-12-24 12:09 ` [PATCH v5 04/14] memory-hotplug: remove /sys/firmware/memmap/X sysfs Tang Chen
2012-12-26 3:30 ` Kamezawa Hiroyuki
2012-12-27 3:09 ` Tang Chen
2013-01-02 14:24 ` Christoph Lameter
2012-12-24 12:09 ` [PATCH v5 05/14] memory-hotplug: introduce new function arch_remove_memory() for removing page table depends on architecture Tang Chen
2012-12-26 3:37 ` Kamezawa Hiroyuki
2012-12-24 12:09 ` [PATCH v5 06/14] memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap Tang Chen
2012-12-25 8:09 ` Jianguo Wu
2012-12-26 3:21 ` Tang Chen
2012-12-24 12:09 ` [PATCH v5 07/14] memory-hotplug: move pgdat_resize_lock into sparse_remove_one_section() Tang Chen
2012-12-26 3:47 ` Kamezawa Hiroyuki
2012-12-26 6:20 ` Tang Chen
2012-12-24 12:09 ` [PATCH v5 08/14] memory-hotplug: Common APIs to support page tables hot-remove Tang Chen
2012-12-25 8:17 ` Jianguo Wu
2012-12-26 2:49 ` Tang Chen
2012-12-26 3:11 ` Tang Chen
2012-12-26 3:19 ` Tang Chen
2012-12-24 12:09 ` [PATCH v5 09/14] memory-hotplug: remove page table of x86_64 architecture Tang Chen
2012-12-24 12:09 ` [PATCH v5 10/14] memory-hotplug: remove memmap of sparse-vmemmap Tang Chen
2012-12-24 12:09 ` [PATCH v5 11/14] memory-hotplug: Integrated __remove_section() of CONFIG_SPARSEMEM_VMEMMAP Tang Chen
2012-12-24 12:09 ` [PATCH v5 12/14] memory-hotplug: memory_hotplug: clear zone when removing the memory Tang Chen
2012-12-24 12:09 ` [PATCH v5 13/14] memory-hotplug: remove sysfs file of node Tang Chen
2012-12-24 12:09 ` [PATCH v5 14/14] memory-hotplug: free node_data when a node is offlined Tang Chen
2012-12-26 3:55 ` Kamezawa Hiroyuki
2012-12-27 12:16 ` Wen Congyang
2012-12-28 0:28 ` Kamezawa Hiroyuki
2012-12-30 6:02 ` Wen Congyang [this message]
2013-01-07 5:30 ` Kamezawa Hiroyuki
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